Our Nirvana Necklaces are constructed using the double spiral chainmail weave and anodized aluminum rings. They contain no lead or nickel and are hypoallergenic. They can be ordered in a wide variety of colors or you can contact us to do custom colors. They are made with 16 gauge 3/8" anodized aluminum rings. 18" is the standard length for these pieces but if you need a different length just let us know.